So, Call of Duty: Black Ops II launched a couple of weeks ago. I care only insomuch that it irritates me how popular it will inevitably prove. Activision is reporting that the game made half a billion dollars in the first twenty-four hours, beating last year’s Modern Warfare 3 as the highest-grossing launch of pretty much anything ever.

Via the incidental stalking power invested in all of us by Facebook, I overheard a friend of a friend discussing his intentions for the launch evening. He announced that he already had not one, but two copies – a PS3 and an Xbox 360 version – in the post from an online distributor, but they weren’t due to arrive until Wednesday morning. Rather than wait the eight or so hours, he was opting to attend a midnight launch, and shell out for a third copy so he could play the game that night.

This is a pretty extreme case, but if it’s indicative of even a portion of Call of Duty fans, I’m not surprised it continues to sell so well. Disappointed and bewildered, but not surprised.

I’m not convinced it’s anything more than Generic Military Shooter #27, and it was completely beyond me why anyone would buy a copy (let alone three) of a game that essentially already came out last year. And the year before that.

But then I reminded myself that I’ve been trying to weasel out of attending a mate’s party later this week. Why? Because the Wii U launches on Friday, and I fully intend to spend that entire weekend on the couch in my underpants, GamePad in hand and one of those sippy-straw hats filled with energy drinks atop my unkempt head.

I maintain that the Wii U is an exciting piece of hardware, so perhaps comparing an annual game franchise to the debutante of the next console generation is a bit unfair. But the software cash-cow milk is on Nintendo‘s hands as well.

While I scoff at Activision customers for buying a slightly different Call of Duty every year, I drink deeply from the regular glasses of homogenised, Mario-flavoured milk that Nintendo keep pouring. I know it’s hypocritical (and disgustingly phrased), but I’m proud to be a sucker.

Super Mario World was the very first video game I owned myself, arriving bundled with our Super Nintendo console one exciting Christmas morning. Since then, I’ve played and beaten all of the core platform games in the series. Each one scratches the itch for a while, but it isn’t long before I have to visit my dealer for another hit of that sweet Mario-Jane.

Super Mario Bros.

From an outside perspective, the differences between entries no doubt look trivial. Bowser elopes with the princess (her willingness is arguable), and Mario – give or take Luigi – uses his mad running, jumping and plumbing skills to give chase across lands of grass, desert, snow and caves, squashing Goombas, eating shrooms and collecting coins along the way.

Evidently that basic backbone is strong enough to support an unholy amount of Mario games over almost thirty years. Each has refined and iterated on the formula in some way, often small, sometimes drastic.

Super Mario Bros. 2 was that multi-character, vegetable-plucking platformer, a massive departure from its predecessor – mostly because it wasn’t originally a Mario game. An obscure Japanese IP was dressed up with Mario characters, after the true SMB2 was deemed too difficult for Western audiences. It later appeared in Super Mario All-Stars, under the guise of The Lost Levels.

SMB3 and World infused the Mushroom Kingdom with more personality, while introducing some series gameplay staples like gliding, Yoshi-riding and the now-necessary world map.

Presenting a pastel, storybook version of the world, Yoshi’s Island changed up the rider/ridee relationship, giving players control of a tribe of Yoshis, trying to carry baby Mario to safety.

When the asteroid of the 3D generation hit, many classic 2D franchises couldn’t adapt to this hostile new environment, and died out, leaving Super Mario 64 to emerge as the dominant species. It shed the rhythmic platforming of its 2D ancestors, and focused on the exploration themes that Miyamoto stressed were integral all along.

Sunshine added that water jetpack, and tricked players into believing that cleaning things could be fun. Galaxy was a beautiful game that experimented joyfully with gravity.

Super Mario Galaxy

The “New” series revelled in a nostalgic backwards-glance to the series’ 2D roots. The Wii entry even let your friends get in the way of your perfectly-timed jumps.

3D Land felt particularly important to me. By merging the exploration of the 3D titles with the flow of the 2D ones, something akin to an alternate-reality Mario 64 was born: Another possible path Nintendo could have guided their portly plumber down, for his first foray into the third dimension.

Finally, the upcoming, unsurprising Wii U version seems to make little use of the hardware’s intriguing capabilities, but one unspoken advantage is playing HD Mario on the GamePad from the comfort of my hammock in the backyard, probably still sans pants. Summer is coming, after all.

Reading back over all that – damn, those Mario games are all kinds of different. Sure, they all involve mustachioed men munching mushrooms, and jumping and running to rescue a princess who either doesn’t want to be rescued, craves attention, or just needs to hire some bodyguards. But it’s a strong recipe, and each time it’s prepared, Nintendo throws a new spice or two into the pot, to keep the regular diners satisfied.

If you’re only an occasional visitor to Mario’s Italian-Japanese restaurant, these changes might go unnoticed or unappreciated. And it works the other way as well: I’m sure changes of varying impact appear in each Call of Duty entry – I just can’t taste them without having sampled the dish a few times.

In the same way that Mario’s speed, weight, jump height, and general movement feels subtly but importantly different in each game, I’d imagine the changes in guns, setting, movement, speed, multiplayer modes, and whatever else would be hugely noticeable, for better or worse, to CoD veterans.

Scorn these fans all you like for drinking down the same formula every year, but I bet there’s a flavour of cash-cow milk that you keep buying. Apparently one big selling point of FIFA12 was a dynamic new system for how people fall over. I don’t get it, but I’m sure it was a big deal to… somebody.

So while I don’t care about the latest Gears of Halo: Battlefield Duty game, I understand why people do. Because I’m totally okay with Nintendo offering me similar experiences reasonably regularly – I like that experience, and I’m happy to pay for new levels or mechanical refinement.

Games are programs, after all, and programs require iteration and refinement to improve.

That’s not to say we should become too complacent about not being given new content or experiences. There are plenty of fascinating original ideas coming out of the industry that need to be tried and supported, but amongst the new, sometimes I just feel like returning to a classic formula.